How do pediatric audiologists test a baby’s hearing?
When a part of the hearing system is not working in the usual way, a pediatric audiologist will test your baby’s hearing to determine the degree and type of hearing loss. Diagnostic hearing testing takes longer than a hearing screening (typically 1-2 hours) and requires your baby to rest or sleep for the duration of testing.
- Auditory brainstem response (ABR) is the gold-standard for determining the softest level of hearing for infants under 6 months of age. ABR provides ear specific and frequency (or tone) specific information necessary for diagnosis of the type and degree of hearing loss.
- A diagnostic ABR test uses small earphones or earmuffs to produce soft sounds into each ear. Band aid-like electrodes are attached to your baby’s skin that detect how sounds are carried to and from the brain. An ABR provides the most information about the softest level of sound your baby can hear.
- Diagnostic ABR testing is painless for your baby.
- Diagnostic ABR is not a screening and will require your baby to sleep during testing (average testing time is 2 hours).
- Diagnostic Otoacoustic Emissions (OAEs) provides important information about how well the inner ear or cochlea receives sound. When the cochlea is functioning normally, it will produce a low-intensity sound or “echo” called an OAE. The OAE is measured and determined to be present or absent.
- An OAE test uses a miniature earphone placed in each ear that produces soft sounds. These sounds generate an “echo” that is measured by a microphone inside the earphone.
- Diagnostic OAE testing is painless for your baby and should be completed while your baby is resting or asleep.
- Diagnostic OAE testing takes much less time than for diagnostic ABR (average testing time is a 5-10 minutes); often both tests can be completed during the same appointment.
- Tympanometry measures the condition of your baby’s middle ear system, which includes the eardrum and middle ear bones. Specialized equipment that produces a high frequency tone is used for very young infants due to the soft, smaller ear canals.
- A tympanometry measurement uses a small probe tip placed in the opening of your baby’s ear canal.
- The probe creates variations of air pressure inside the ear canal.
- Tympanometry is painless for your baby and should be completed while your baby is resting or asleep.
- Tympanometry testing takes about 5-10 minutes to complete.
- Visual Reinforcement Audiometry (VRA) is a hearing test for babies 6 months to 36 months of age who are able to sit up and turn their head, while sitting on a caregiver’s lap. As your baby grows, behavioral testing in a sound booth allows for more specific “plotting” of hearing test results using an audiogram (graph showing hearing test results).
- During VRA testing, sounds are presented to baby inside the sound booth, through speakers, headphones or earphones.
- A light or moving toy will activate when baby turns toward the sound.
- Speech may also be presented to check how well your baby responds to speech sounds.
- The audiologist presents sounds at the lowest level (threshold) to find out how your baby can detect sound at different frequencies (or pitch levels).